2Topics1. What is Cloud Computing?2. The Same Old Security Problems3. Virtualization Security4. New Security Issues and Threat Model5. Data Security
3What is Cloud Computing?“Cloud computing is a model for enabling conveni-ent, on-demand network access to a shared pool ofconfigurable computing resources (e.g., networks,servers, storage, applications, and services) thatcan be rapidly provisioned and released with mini-mal management effort or service provider interac-tion.” NIST definition of Cloud Computing
8Same Old Security Issues1. Data Loss2. Downtimes3. Phishing4. Password Cracking5. Botnets and Other Malware
9Data Loss "Regrettably, based on Microsoft/Dangers latest recoveryassessment of their systems, we must now inform you thatpersonal information stored on your device—such as contacts,calendar entries, to-do lists or photos—that is no longer onyour Sidekick almost certainly has been lost as a result of aserver failure at Microsoft/Danger.”
14Virtualization Security1. Features 1. Isolation 2. Snapshots2. Issues 1. State Restore 2. Hypervisor Security 3. Inner-VM Attacks 4. Scaling
15Isolation• More than running 2 apps on same server• Less than running on 2 physical servers
16Snapshots• VMs can record state• In event of security incident, revert VM back to an uncompromised state• Must be sure to patch VM to avoid recurrence of compromise
17State Restore• VMs can be restored to an infected or vulnerable state using snapshots.• Patching becomes undone.• Worms persist at low level forever due to reappearance of infected and vulnerable VMs.
19Inner-VM Attacks• Attack via shared clipboard• Use shared folder to alter other VM’s disk image
20Scaling• Growth in physical machines limited by budget and setup time• Adding a VM is easy as copying a file, leading to explosive growth in VMs• Rapid scaling can exceed capacity of organization’s security systems
21New Security Issues1. No Security Perimeter2. Larger Attack Surface3. New Side Channels4. Lack of Auditability5. Data Security
22No Security Perimeter• Little control over physical or network location of cloud instance VMs• Network access must be controlled on a host by host basis
23Larger Attack Surface Cloud Provider Your Network
24New Side Channels• You don’t know whose VMs are sharing the physical machine with you. ▫ Attackers can place their VMs on your machine. ▫ See “Hey, You, Get Off of My Cloud” paper for how.• Shared physical resources include ▫ CPU data cache: Bernstein 2005 ▫ CPU branch prediction: Onur Aciiçmez 2007 ▫ CPU instruction cache: Onur Aciiçmez 2007• In single OS environment, people can extract crypto graphic keys with these attacks.
25Lack of Auditability• Only cloud provider has access to full network tr affic, hypervisor logs, physical machine data.• Need mutual auditability ▫ Ability of cloud provider to audit potentially malici ous or infected client VMs. ▫ Ability of cloud customer to audit cloud provider e nvironment.